The more I drive the more I wonder "how would a computer handle that?". Assuming the computer will always follow the rules and the company will not want to take liability for any "gray area" maneuvers or difficult driving situations, I expect the "override" feature will be used often. The car companies will not want the liability. What is the point of an autonomous car when it still needs a driver to take control? There are a lot of legal issues to work out.